"It is time for a new kind of leadership in Washington that's committed to using our lands in a responsible way to benefit all of our families," Obama said in a news conference, his third in as many days to announce Cabinet choices.
On another subject, Obama said "it's a little bit frustrating" to not talk in detail about the investigation into charges that Illinois Gov. Rod Blagojevich schemed to name Obama's replacement in the U.S. Senate based on who offered the best political or financial deal. Blagojevich was arrested last week by the FBI.
Neither Obama nor anyone on his team has been accused of any wrongdoing in the probe. But the president-elect has directed transition aides to detail who on his side had contact, and what kind, with Blagojevich or his staff.
"There's been a lot of speculation in the press that I would love to correct immediately," Obama said in response to a question. He said his team is "abiding by the request of the U.S. attorney" to not release the results of the internal investigation, already compiled, until next week. "It's not going to be that long," Obama said.
For the agriculture and interior departments -- which oversee federal farming and lands policies -- Obama said his approach will be to "serve not big agribusiness or Washington influence peddlers but family farmers and the American people."
He said this means promoting not only development but protection of environmental treasures and expanding both agriculture and new energy sources.
"I am confident we have the team we need to make the rural agenda America's agenda, to create millions of new green jobs, to free our nation from its dependence on oil and to help preserve this planet for our children," Obama said.
Transition officials say more announcements are likely this week before Obama heads to Hawaii for Christmas vacation with his family.
Vilsack is be the fourth former opponent of Obama in the campaign for the 2008 Democratic presidential nomination to join his administration. Others include Vice President-elect Joe Biden, Sen. Hillary Rodham Clinton, who has been tapped for secretary of state, and New Mexico Gov. Bill Richardson, selected to head the Commerce Department.
Vilsack announced his presidential candidacy in late 2006, positioning himself as a Washington outsider with heartland appeal, but he dropped out before the primaries because he had trouble raising money. He endorsed Clinton and campaigned actively for her in the long primary campaign against Obama. After Obama defeated Clinton, Vilsack endorsed him.
First elected governor in 1998, Vilsack, 58, carved out a reputation as a political centrist. He balanced Iowa's budget and resisted raising taxes, but was willing to spend on such priorities as education and health. He argued that pushing alternative energy sources was key to bolstering rural sections of the nation that are struggling economically.
"Tom will not only help ensure that rural America has a true partner in implementing the farm bill and pursuing agricultural research, but that Washington is looking out for everyone, from the small family farms that are feeding our communities to the large farms that are feeding the world," Obama said.
Salazar will head a department that oversees oil and gas drilling on public lands and manages the nation's parks and wildlife refuges. He is expected to try to balance protection of natural resources with use of the nation's energy potential -- an approach Obama said in the announcement that he wants.
"I will do all I can to help reduce America's dependence on foreign oil," Salazar said, wearing a cowboy hat and string tie. "I look forward to working directly with President-elect Obama, as an integral part of his team, as we take the moon shot on energy independence."
Salazar co-sponsored a bill in Congress to create a new land conservation system under the Interior Department's Bureau of Land Management for permanently protecting 26 million acres of national monuments, wilderness areas and wild and scenic rivers. The legislation died during the special session of Congress after the November election.
The Colorado senator opposed drilling in Alaska's Arctic National Wildlife Refuge and objected to the Bush administration's efforts to lease Western lands for oil shale development. It will be up to the Obama administration whether to go ahead with leasing.
If Salazar is confirmed as interior secretary, Colorado Gov. Bill Ritter, a Democrat, will name a replacement to serve out the final two years of his term. Before being elected to the Senate in 2004, Salazar was Colorado's attorney general. He also headed the state's Natural Resources Department from 1990-1994.